Improvement in sewing-machines



J. HARRISON-Jr.

Sewing Machine.-

No: 13,616. Patented 0m. 2, 1.855.

N. PETERS Pholblilhognphen Washington. D, c.

I UNITED STATES PATENT OFFICE.

JAMES HARRISON, JR, OF MIL\VAUKEE, XVISCONSIN.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 13,616; dated October2, 1855.

I0 all w/wm', it may concern.-

Be it known that I, Jxarns HARRISON, J r., of the city and county ofMilwaukee, and State of \Visconsin, have invented certain new and usefulImprovements in Sewing Machines; and I do hereby declare that thefollowing is a full, clear, and exact description of the same, referencebeinghad to the accompanying drawings, forming part of thisspecification, in which 'Figure l is a side elevation of a machine withmy improvements, represented with a part of its bed=plate cut away toshow the working parts. Fig. 2 is a front elevation of the same, alsorepresenting the bed plate partly cut away to show the workingparts.Fig. 3 is a longitudinal section of one of the needle guide plates. Fig.4 is a detail view of a portion of the machine. Fig. 5 is a top view ofthe top clamping-plate, which holds the material to be sewed; and Fig. 6is a longitudinal section of the same.

Similar letters of reference indicate corresponding parts in the severalfigures.

This invention relates to that description of sewing-machines in whichthe seam is formed by the interlacing of two threads, which are carriedthrough the material to be sewed, from opposite sides thereof, in theform of loops by two needles arranged obliquely to the material andoperating by turns, each to pass its loop through the loop previouslypassed through the material by the other, such machine being generallyknown "as the Avery Sewing-Machine.

The object of one part of this invention is to give the cloth or othermaterial to be sewed the movement known as the feed movementindependently of the needles, instead of by the needles, as in the Averysewing-machine; and for this purpose this part of my invention consistsin giving the needles such a movement that both are for a time withdrawnfrom the cloth to leave it free to be acted upon by suitable feedingmechanism, and in providing a third or supplementary needle to catch theloop which is last passed through the material before the withdrawalofthe needles, .and retain it until after the feed movement has takenplace and until the next loop is passed through it.

The object of the other parts of my invention is to provide means ofholding the material to be sewed, which admit of its being liberatedbefore and during the feed movement; also, means of causing theinterlacings of the two threads, when the seam is formed, to'be alwaysclose to or as close as desirable to one surface of the material,whatever may be the thickness of the material and notwithstanding anyvariations in its thickness.

To enable those skilled in the art to make and use my invention, I willproceed to describe its' construction and operation.

A B B is the framing of the machine, close under the bed-plate B ofwhich are secured the bearings for the horizontal main shaft 0, whichcarries a cam, D, to operate two elbow-levers,

F F, which drive the two sliding needle-bars I E E. This cam is soconstructed that thelower needle, a, passes through the cloth or othermaterial to be sewed (which is represented in Fig. 2 by a double blueline) as quickly as possible after the loop of the thread of the upperneedle, a, has been formed, and is withdrawn as quickly as possibleafter the upper needle, so that nearly one-fourth of the revolution ofthe main shaft may be performed before the point of the upper needlenext enters the cloth, thus leaving the material entirely free of theneedles during so much of the revolution; but before the lower needle iswithdrawn the supplementary needle I) enters its loop to retain itandhold it in readiness for the upper needle, a, to pass through it on itsnext movement to pass through the cloth.

The supplementary needle I) is attached to or forms part of a bar, I),which slides in a guide at the side of and nearly parallel with theneedle-bar E, said guides being in the same plate, G, as the guide ofthe said needle-bar, and

the said supplementary needle is connected by ahook at its upper endwith an elbow-lever, c 0, which is pivoted to the guide -plate G. Thisbar I) is fitted to its guide in the guideplate G in such a manner thatit isallowed to vibrate or move sidewise a limited distance, and hasWound round it a spring, d, which gives it a downward pressure, andwhich by reason of its upper end being extended sidewise and caused topress under the guide-plate G on the side nextto the needle-bar E, ass1. own in Fig. 2, has a tendency to throw the point of thesupplementary needle I) always away from the needle a. The abovetendency is controlled by a screw, e,,(see Fig. 2,) which is screwedinto the fixed plate H, to which the guide-plate G is attached, andwhich regulates the position of the point of the supplementary needlewhen the latter is free of the cloth. During the whole time, or'nearlyso, that the needle (4 is in the cloth the supplementary needle islifted up by reason of the swelled part f of the needle-bar E havingthrown aside the upper and raised the lower arm of the elbowlever c c,to which the supplementary needle is attached; but as the needle a iswithdrawn from the cloth and the swelled .part f of the needle-barleaves the lever c c, the supplementary needle is forced down by itsspring d until it passes close behind the lower needle, a, and betweenthe said needle and its thread in the same manner as the needle a woulddo if descending at the same time, and its point passes through thecloth, as shown in Fig. 2, and then it remains stationary until.thelower needle has been withdrawn and left its thread in the form of aloop around it. The feedmovement, which is in the direction of the arwayinterrupted by the supplementary needle,

as that is allowed to move with the cloth, by

which it is drawn toward the needle a, which on its next descent, whichtakes place while b remains in the cloth, passes close to it and throughthe open part of the loop, between I) and where the loop leaves thecloth, I) being withdrawn from the loop by the action of the swelledpart f of the needle-bar E on the lever c c at the same time the needlecenters it. In order to insure the proper action of the supplementaryneedle in receiving the loop from the needle a and giving it to theneedle b, a slight movement laterally to theline of the sewing isnecessary, and for this purpose there is a small oblique guide-piece orprojection, 8, onthe back side of the hole i, through which the needlespass in the top one of the clamps I, which hold the cloth during thesewing operation. The supplementary needleat the time of entering theloop and the cloth, when it has to pass behindthe needle a, passesopposite the right-hand end of this guide-piece, which is the leastprominent part; but during the feed movement of the cloth it is drawnalong the face of this projection, and thus thrown a little forward toplace it directly in line with the needle a, so that the latter shallpass through the center of the loop.

The feeding mechanism, as I do not intend to claim it as a part of thisinvention, needs no particular description. Suffice it, then, to saythat it consists of a toothed spring-dog, j, attached to a sliding bar,J, below the table A, and moved by a cam, J, on the main shaft 0, whichserves the purpose of raising the dog as well as of moving the feed-barlongitudinally by coming in contact with a projection, 1), on its underside, the bar being returned, to be in readiness to repeat its action,by a spring, 00. There may be other feeding mechanism which would servethe purpose.

The clamps I I, between which the cloth is held to be sewed, consist oftwo flat plates, which are jointed each by knuckleoints p p to one oftwo forked-rods, k k, which are rigidly attached one to each of theguide-plates G G, in which the needle-bars E E slide. These guide-platesswing each on a center near the end farthest from the needle, as shownin Fig.2, being attached to the fixed framing of the machine in thefollowing manner, which is illustrated in Figs. 1, 2, and 3.

H H are'two plates secured by screws m m, respectively, to the two heads13 B of the framing, having circular openings in them to receive largepivots I, (see Fig. 8,) which form parts of or are secured to theguide-plates G G", and which constitute the centers on which theguide-plates swing. The external form of the fixed plates H H. is shownin Fig. 2, as also are the slots at a, through which work the levers FF, by which the needle-bars are driven. The form of the guide-plates G-G, which are behind the plates H H, is nearly the same as that of thefixed plates H H; but they have openings not only for the passage of thelevers F F through them, but 'also for the heads B B of the frame-work,and at the ends nearest the plane of the sewing they extend a littlebeyond the ends of the fixed plates, as shown at o o in Fig. 2, and fromthence extend forward and contain shallow grooves to receive the ends ofthefixed plates. The parts 0 0 of the guide-plates contain grooves toform guides for the needle-bars, and so do the pivots Has theneedle-bars swing with the guide-plates, the said grooves in 0 0 beingcovered and closed in front by plates 0 0, and those in the pivots bycaps Z Z, which fi't over the said pivots and are secured thereto byscrews. The object of attaching the clamps I I to the guide-plates ofthe needlebars and giving a swinging movement to theguide-plates is toallow the clamps to accommodate themselves to different or varyingthicknesses of material without adj ustment, and at the same time topreserve the proper crossingpoint of the needles. The swinging movementof the clamps also allows the material to be liberated or their holdupon it to be loosened during the feed movement, all of which will bepresently explained. The face of the bottom clamping-plate, I, which isthe plane in which I desire the interlacing of the loops to beperformed, in order never to show anything but a single thread 011 theupper surface of the material, forms a plane which nearly bisects or isnearly parallel with a plane bisect ing the angle formed by the lines ofmotion of the needles, and is kept in that position during the vibratingmotion of the guide-plates by connecting the plate I at one end byarod,q, to the side of the fixed plate H. The lower point of attachment ofthe rod q and the center of the pivotZ thus both being fixed points andbeing equidistant with the upper point of attachment and the center ofthe joint 12, and the rod q being of the same length as from the centerZ to the center the plate I must have a sary that the relation betweenthe movements furnishing the connection between the links R is attachedto the arm by a binding-screw, and

parallel movement. The upper clamp, I, being suspended in one transverseline, accommodates itself to any variation in the thickness of that partof the cloth which is at any time passing under it. The pressure givento the clamps I I to confine the cloth is slightly yielding, beingproduced by a spring, Q, acting on two levers, H M, at the rearextremities of two shafts, N N, which rest inbearings w 10, attached tothe heads B B of the framing, the front ends of the said shafts carryingarms P P, which are respectively connected by links R R with theguide-plates G G. These levers M M, which, with their shafts and springand the main shaft 0, are shown in Fig. 4, are connected together by apair of links, R*, for the purpose of controlling the relative movementsof the two guide-plates, and through them of the two needles to a andclamps, as it is necesshould be very correctly preserved to keep thecrossingpoint of the needles,which is the point of interlacing of thethreads, always in the plane of the lower surface of the material or ofthe face of the clamp I. The position 'of this plane varies as thethickness of material varies, descending with an increased and risingwith a diminished thickness, and in order to make the crossing-point ofthe needles follow it, it is necessary that the lower needle, needlebar,guideplate, and clamp shall have a lateral movement considerably greaterthan the upper ones, and therefore the point of connection between thelevers M M is much nearer to the shaft or fulcrum of the lower lever, M,than to the shaft or fulcrum of the upper le ver to produce suchrelative movements. As it is not easy to fix the relative effectivelengths of the levers exactly, owing to accidental deviations in thelengths of the various connec tions, a means of regulating the relativemovements of the guide-plates G G is provided by and the arm I with asliding piece, 1', which is movable to vary the effective length of thearm. The rods L k,which connect the clamps with the guide-plates G G,and the rod g, which connects the lower clamp with the fixed plate H,are also variable by screws and nuts to adjust the clamps higher orlower. The opening or slacking of the clamps to release the cloth orrelax their pressure upon it during the feed movement is produced by awiperstud, s, on the main shaft 0 (see Fig. 4) acting on an angle-piece,t, attached to the lever M. The amount of movement given to the clampsis regulated by a hinge-piece, t, which is attached at the angle-piece,and has its position relatively thereto regulated by a screw, tithe saidwiper-stud acting upon the angle-piece by impinging against thehinge-piece.

The control of the feed to make it always proportionate in the inverseratio to the thickness of the material being sewed, or of that part ofthe material passing between the clamps, is

effected by the upper end of the arm P,which serves as a stop to arrestthe feed-bar J when the said bar is returned by the spring 00 after thecam ceases to act on the projection v. The length of the feed may beincreased or diminished by a screw, m, which is attached to thefeed-bar, and which comes in contact with the arm P to arrest thebackward movement of the feed-bar.

The machine may be made much more sim- 'will proceed to state what Iclaim as new and desire to secure by Letters Patent.

1. In combination with the giving of the two needlesa a such a movementas will cause both at once, during every revolution or stroke of themachine, to be withdrawn from the cloth for a sufficient time to effectthe feed movement, I claim the employment of a supplementary needle, 1),arranged and operating, substantially as herein described, to supply theplate of the needle a, which operates first after the feed movement, andto retain the loop in the thread which has been put through the cloth bythe needle which last leaves the cloth before the feed movement untilthe first named needle operates to pass through the said loop,substantially as herein described.

2.: The attachment of the clamps I I,which hold the material to be sewedto two swinging guide-plates, G G, or their equivalents, which servealso as guide-plates for the needle-bars, and thereby cause the needlesand the clamps to swing together, substantially as herein described,whereby the clamps are enabled to accommodate themselves to different orvarying thicknesses of material, and to be opened to slacken their holdupon the mate rial during the feed movement, and the needles are enabledto be kept in a proper or desirablerelation to the clamps. I

3. The connection of the two swinging guide. plates G G or theirequivalents in any manner, substantially as herein described, where byone of them is caused to have a movement so much greater than the otherthat the relative movements of the needles and clamps shall be such thatthe needles in all positions of the clamps will cross each other in theplane of or as near as is desired to the plane of the face of one of theclamps, which is the plane of one surface of the material, as here infully set forth.

JAS. HARRISON, J R.

